Conduit Fill is the percent of area inside the conduit taken up by the cable(s). Provides quick and easy results for the conduit fill percent, per NEC® guidelines.

What is maximum fill rate for conduit?

The National Electrical Code establishes that if a conduit only contains 1 wire, the max fill percentage is 53%. If it contains 2 wires, the max fill percentage is 31%. And if it contains 3 or more wires, the max fill percentage is 40%.

Do you count the ground in conduit fill?

No! The main consideration in conduit fill is the heating caused by the current carrying conductors. Since the ground wire only carries current under fault conditions it is not counted in the conduit fill calculations.